Pitot pumps are often used when fluids of high pressures and low flow rates are to be delivered to a utilization device. Conventional pitot pumps utilize a fixed probe having an inlet comprising a hole disposed in a tip of the probe and an outlet wherein the cross sectional area of the probe flow path increases from the inlet to the outlet. The probe and probe tip are disposed in a body of rotating fluid within a rotating housing such that the hole in the probe tip faces the flow of rotating fluid. The fluid is diffused after entering the probe to convert dynamic pressure into static pressure.
Pitot pumps typically experience drag losses due to flow of the liquid in the housing past the probe. Prior attempts at reducing these drag losses have focused primarily on probe geometry and cross sectional configuration. By streamlining the probe, significant reduction in drag losses can be accomplished.
Bland, U.S. Pat. No. 4,679,980, assigned to the the assignee of the instant application, discloses an inventory control device for a two-phase flow system. The device utilizes a pitot pump comprising a rotating housing, a conventional pitot tube stationarily mounted within the rotating housing and a second pitot tube in fluid communication with an accumulator. During operation of the pitot pump, liquid is disposed in an annular space surrounding vapor within the rotating housing. A pressure relation is established using the accumulator whereby the second pitot tube and the accumulator maintain a constant level of liquid within the rotating housing of the pitot pump. The fluid level is controlled for the purpose of achieving good centrifugal separation of gas and vapor or for the purpose of maintaining constant angular momentum of the rotating housing.
Tarifa, U.S. Pat. No. 3,093,080 discloses a pitot pump wherein an inlet into a rotating housing of the pump rotates at a speed of about one-half the housing speed to inject fluid smoothly into the partially filled housing without disturbing the free surface. The level of the liquid of the rotating housing is controlled by either a hydrodynamic shoe actuated throttle plate or by a reverse scoop which disturbs the incoming flow.
Zupanick, U.S. Pat. No. 3,936,214 discloses a pitot pump which may be used as a centrifugal separator. A stationary arm is disposed within a rotating housing containing two-phase fluid flow. The stationary arm includes a first orifice at an outward end of the arm and a second orifice at an inwardly disposed position of the arm. A sensor is used to detect the type of fluid being received at the second orifice. If the fluid is liquid, a control valve closes the exit passage in fluid communication with the second orifice and the speed of rotation or rate of mixed phase fluid flow into the pump is altered to achieve proper balance between phases.
O'Mara, U.S. Pat. No. 3,671,136, Erickson, U.S. Pat. No. 3,776,658, Erickson, et al., U.S. Pat. No. 3,795,459, Erickson, et al., U.S. Pat. No. 3,817,659 and Crichlow, U.S. Pat. No. 4,280,790 disclose pitot pumps wherein one or more pitot tubes are disposed in a rotating chamber or housing.
Prince, U.S. Pat. No. 2,541,831 discloses a rotating magnetic clutch assembly wherein centrifugal forces are utilized to remove fluids in a space between relatively rotatable members to prevent viscous drag when the clutch is disengaged.